Bicyclic heterocyclic tertiary phosphine-cobalt-carbonyl complexes



United States PatentO ABSTRACT OF THE DISCLOSURE Novel catalysts ofcobalt in complex combination with carbon monoxide and a ibicyclicheterocyclic tert-phosphine for use in an improved hydroformylationprocess to elfect the direct, single-stage production of reactionproducts consisting predominantly of primary alcohol by reacting anolefinic compound with carbon monoxide and drogen at a temperaturebetween about 100 and 300 C. and superatmospheric pressure in thepresence of said catalyst.

CROSS-REFERENCES TO RELATED APPLICATIONS This application is acontinuation-in-part of copending application of J. L. Van Winkle, R. C.Morris, and R. F. Mason, U.S. Ser. No. 468,573, filed June 30, 1965, andnow US. 3,420,898, and also is a continuation-inpart of copendingapplication of J. L. Van Winkle, R. C. Morris, and R. F. Mason, U.S.Ser. No. 493,555, filed Oct. 6, 1965, now US. 3,440,291.

BACKGROUND OF THE INVENTION Processes directed to the production ofreaction mixtures comprising substantial amounts of aldehydes and attimes lesser amounts of alcohols by the reaction of olefinic compoundswith carbon monoxide and hydrogen at elevated temperatures and pressurein the presence of certain catalysts are well known in the art. Thealdehydes and alcohols produced generally correspond to the compoundsobtained by the addition of a carbonyl or carbinol group to anolefinically unsaturated carbon atom in the starting material withsimultaneous saturation of the olefin bond. Isomerization of the olefinbond may take place to varying degrees under certain conditions with theconsequent variation in the products obtained. These processes known inthe industry and referred to herein as hydroformylation involvereactions which may be shown in the general case by the followingequation:

and/ or R2 l a R1CH?CHzOH isomeric alcohols and aldehydes In the aboveequation, each R represents an organic radical, for example hydrocarbyl,or a suitable atom such as hydrogen. The above reaction is similarlyapplied to an olefinic linkage in a cycloaliphatic ring.

A disadvantage of hydroformylation processes disclosed heretofore istheir dependence upon the use of catalysts, such as dicobaltoctacarbonyl, which generally necessitate the use of exceedingly highpressures to remain stable under the conditions therein employed. Afurther disadvantage of many of the processes disclosed heretofore istheir inability to produce hydroformylation products directly comprisingsubstantial amounts of alcohols, thereby necessitating a separatealdehyde hydrogenation step when alcohols are a desired product. Theproduction of hydroformylation products having a relatively high normalto branched product isomer ratio is often also exceedingly difficult ifat all possible in many of the practical scale processes heretoforedisclosed.

In US. Patent 3,239,569, issued Mar. 8, 1966, to L. H. Slaugh et al., isdescribed a hydroformylation process to effect the direct, single-stagehydroformylation of olefins to a reaction mixture wherein the alcoholspredominate over the aldehydes, utilizing substantially lower pressuresand a cobalt catalyst comprising cobalt in complex formation with carbonmonoxide and a phosphorous-containing ligand consisting essentially of atertiary organophosphine, such as tri-n-butylphosphine.

A shortcoming in the aforementioned process utilizingtrihydrocarbylphosphines such as tributylphosphine is the conversion ofa portion of the starting olefin to saturated hydrocarbon, a sidereaction decreasing the yield of the desirable and commercially valuablealcohol product. Another is a relatively slow rate of hydroformylation.

Therefore, it is an object nf the present invention to provide novelcatalysts for use in an improved hydroformyl-ation process to effect thedirect, single-stage hydroformylation of olefins to produce reactionproducts consisting predominantly of primary alcohols and at the sametime to reduce the quantity of side-reaction forming saturatedhydrocarbon.

SUMMARY OF THE INVENTION In accordance with the present invention,olefinic compounds are converted to primary alcohols having one or morecabon atoms than the olefinic compounds by reacting the olefiniccompounds in liquid phase, with carbon monoxide and hydrogen, at atemperature between about 100 and about 300 C. in the presence of anovel catalyst comprising cobalt in complex combination with canbonmonoxide and a particular class of tertiary organophosphines. Thespecific class of tertiary organophosphines, which is a suitable ligandof the novel cobalt-containing catalysts of the present invention, is abicyclic heterocyclic tert-phosphine. Generically, these compounds arehydrocarbyl-substituted monophosphabicyclohydrocarbons, saturated orunsaturated, of 8 to 9 atoms in which the smallestphosphorous-containing ring contains at least 5 atoms, and thephosphorous atom therein'is a member of a bridge linkage but is not abridgehead atom. In addition to the hydrocarbyl substitution on thephosphorous atom, the ring carbons may also be substituted. However, itis preferred that such C-substituents be limited to non-bulky ones.

DESCRIPTION OF PREFERRED. EMBODIMENTS In their active form, thesuitable" novel complex catalysts contain the cobalt in a"r"ediicedvalence state. This will normally be a zero valence state and maysuitably be even lower, such as a l valence-state. As used throughoutthis specification and claims, the term complex means a coordinationcompound formed by the union of one or more electronically richmolecules or atoms capable of independent existence with one or moreelectronically poor molecules or atoms, each of which is also capable ofindependent existence.

In the suitable special class of ligands described hereinaftercontaining trivalent phosphorus comprised in the novel complex catalystemployed in the process of the invention, the phosphorus atom has oneavailable or unshared pair of electrons. When trivalent phosphorus hassuch an electronic configuration, it is capable of forming a coordinatebond with cobalt in its and 1 valence state. It will thus operate as aligand in forming the desired novel cobalt complexes used as catalystsin the present invention.

A particularly useful group of bicyclic heterocyclic tert-phosphines, inwhich the bicyclic portion of the molecule is saturated, includeshydrocarbyl-substituted monophosphabicycloalkanes having from 8 to 46carbon atoms, preferably from 12 to 40, and which is represented by theformula (c/Rz)y mm). o

wherein Q represents hydrocarbyl, y and z represent positive integerswhose sum is from 2 to 3 and each of which has a minimum value of 1, andR represents hydrogen and lower alkyl of from 1 to 4 carbon atoms, suchas methyl, ethyl, propyl, and butyl. It is preferred that no more thantwo R groups be alkyl at any one time and that each of these by attachedto a different ring carbon. It is to be understood that in the foregoinggraphic formula and those appearing hereinafter the line portion of thestructure represents a conventional organic chemical covalent bond withsaturated carbon atom at each indicated intersection, the saturationbeing by the required number of hydrogen atoms or hydrocarbyl radicals.

The term hydrocarbyl is used in its accepted meaning as representing aradical formed from a hydrocarbon by removal of a hydrogen atom. Thehydrocarbyl groups represented by Q in the formula above may be anynonacetylenic organic radical composed solely of carbon and hydrogen.The widest variation is possible in that the (non-acetylenic)hydrocarbyl group may be alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl,aralkyl, alkary], single ring, multi-ring, straight chain, branchedchain, large or small. Representative hydrocarbyl groups include methyl,ethyl, methallyl, n-butyl, hexyl, hexenyl, isooctyl, dodecyl, oleyl,octadecyl, eicosyl, hexacosyl, octacosyl, triacontyl, hexatriacontyl,tetracontyl, cyclohexyl, cyclooctyl, cyclooctenyl, phenyl, naphthyl,benzyl, styryl, phenethyl, and the like. Thus, a particularly usefulclass of bicyclic heterocyclic tert-phosphines is that containing onlycarbon, hydrogen, and phosphorus atoms.

Substituted hydrocarbyl groups are also operable and may contain afunctional group such as the carbonyl, carboxyl, nitro, amino, hydroxy(e.g. hydroxyethyl), cyano, sulfonyl, and sulfoxyl groups. Aparticularly useful group of ligands consists of those in which Q ishydrocarbyl of from 1 to 36 carbon atoms; especially preferred are thosein which Q is hydrocarbyl of from 4 to carbons.

Hence, a preferred group of bicyclic heterocyclic tertphosphinesincludes those represented by the formula where Q represents hydrocarbylof 1 to 36 carbons and especially of 4 to 30, y and 2 represent positiveintegers whose sum is from 2 to 3 and each of which has a minimum valueof 1, and R is a member selected from the group consisting of hydrogenand alkyl of 1 to 4 carbons such that no more than two R groups arealkyl at any one time and that each of said alkyl groups is attached toa different ring carbon.

It is sometimes desirable to balance the size of the substituents in theaforedescribed phosphines. When the R substituents are relatively large,e.g. butyl, it may be desirable to choose a smaller Q. Conversely, whenQ is large, e.g. eicosyl or hexatriacontyl, it may be desir- 4 able thatthe R substituents be smaller and/or less numerous, such as monomethylor dimethyl. Particularly useful ligands are those in which the sum of Rand Q is no greater than 38 carbon atoms and those in which the totalnumber of carbon atoms is no greater than 46.

The monophosphabicycloalkanes in which the phosphorus atom issubstituted with hydrocarbyl are described in copending U.S. applicationof R. F. Mason et al., Ser. No. 468,572, filed June 30, 1965, now U.S.3,400,163. Thus, they may be prepared by the reaction of a primaryphosphine with suitable cyclic diolefinic compounds. For example,9-hydrocarbyl-9 phosphabicyclononanes, in which the smallestphosphorus-containing ring contains at least 5 atoms, are derived from1,5-cyclooctadienes, including those with ring carbon substituents,which in turn are obtainable by'the cyclo-dimerization of conjugateddiolefins, such as butadiene and isoprene. Similarly8-hydrocarbyl-8-phosphabicyclo[3.2.1]octanes can be obtained from1,4-cycloheptadiene and substituted 1,4-cycloheptadienes. Unsaturatedmonophosphabicyclohydrocarbons in which thephosphorus atom issubstituted with hydrocarbyl are obtainable from the aforementionedmonophosphabicycloalkanes. The P-hydrocarbyl monophosphabicycloalkane isfirst converted from a tertiary phosphine to a phosphine oxide byconventional methods, e.g., air oxidation, to protect the phosphorusgrouping in the subsequent halogenation step. Halogenation, e.g. withbromine, places one or more halogen atoms in the ring structureespecially at the bridgehead carbon positions. Dehydrohalogenation, e.g.removal of HBr by heating with concentrated alcoholic-KOH or tertiaryamine, yields the corresponding unsaturated phosphine oxide. Theunsaturated phosphine oxide is then reduced to the desired unsaturatedtert-phosphine, i.e. the P-hydrocarbyl unsaturatedmonophosphabicyclohydrocarbon, by reduction of the P O groupto P bytreatment with a silicon compound containing one or more Si-H bonds or aprecursor thereof, by the methods describedin Canadian Patents 694,465,issued Sept. 15, 1964; 701,926, issued Jan. 12, 1965; and 707,769,issued Apr. 13, 1965.

Another group of bicyclic heterocyclic tert-phosphines which aresuitable ligands of the novel cobalt-containing catalysts of the presentinvention and in which the bicyclic portion of the molecule isunsaturated, are hydrocarbylsubstituted monophosphabicyclononatrienes. Aparticularly useful group of such phosphines includeshydrocarbyl-substituted monophosphabicyclononatrienes having from 9 to44 carbon atoms, preferably from 12 to 38, and which is represented bythe formula (III) wherein Q represents hydrocarbyl as definedhereinahove.

Hence, a preferred group of P-hydrocarbyl monopho'sphabicyclononatrienesincluding those represented by the formula where Q representshydrocarbyl of 1 to 36 carbons and especially of 4 to 30.

The monophosphabicyclononatrienes in which the phosphorus atom issubstituted with hydrocarbyl are particularly advantageous and valuablebecause they may be prepared from readily available materials. They maybe produced by the reaction of a di(alkali metal) salt of a suitablecyclic tetraolefinic compound with hydrocarbylphosphonous dihalides,especially dichlorides, which are readily available. For example,9-hydrocarbyl-9- phosphabicyclononatrienes, in which the smallestphosphorus-containing ring contains at least 5 atoms, are derived fromdi(alkali metal) salts of cyclooctatetranene, which in turn areobtainable by the low-temperature reaction of cyclooctatetraene with analkali metal, especially potassium, lithium, or sodium and preferablypotass1um. Cyclooctatetraene is readily available from thecyclotetramerization of acetylene. The aforesaid di(alkali metal) saltis then reacted with a hydrocarbylphosphonous dihalide, preferably adichloride. This reaction step may often proceed with violence;therefore, low temperatures are recommended. Both steps are convenientlycarried out in a dry solvent inert to reaction with alkali metal.Suitable solvents include ethers such as tetrahydrofuran, dioxane, andthe like. The P-hydrocarbyl monophosphabicyclonatrienes may be recoveredfrom the solvent by conventional methods, e.g. distillation, filtration,sublimation and the like. By way of illustration, 22.3 g. of potassiumcut into small ortions was added to 250 ml. of tetrahydrofuran, dried byprevious distillation from LiAlH This mixture was cooled to 75 C. and toit, over a period of /2 hour, was added dropwise 26 g. ofcyclooctatetraene. The resulting material was stirred at -72 C. for 4hours. The temperature was raised to 16 C. and held there for hoursduring which time yellow crystals for-med. The slurry was diluted with250 ml. of dry tetrahydrofuran and filtered through a glass wool plug toremove unreacted potassium into a dropping funnel. The above operationswere conducted under N In a reaction kettle was placed 0.27 mole ofphenylphosphonous dichloride diluted with 100 ml. of drytetrahydrofuran. The contents of the kettle were cooled to 20 C. and thesolution of the di(potassium) salt of cyclooctatetraene was addeddropwise over 1 hour thereto. The resulting reaction mixture was allowedto warm to room temperature and stirred for 6 hours. To this was added300 ml. of butanol, followed by 300 ml. of ether saturated with waterand 500 ml. of water. The mixture was stirred for 1 hour and then theorganic layer was separated therefrom. The organic layer was evaporatedto dryness and the remaining solid mass was sublimed at 0.3 mm. Hg and150 C. to produce 8.5 g. of9-phenyl-9-phosphabicyclo[4.2.1]nona-2,4,7-triene, a white crystallinesolid.

Suitable and novel catalysts of the invention include the tertiaryorganophosphine-cobalt-carbonyl complexes consisting essentially ofcobalt in complex combination with carbon monoxide and a bicyclicheterocyclic tertphosphine and represented by the empirical formulawherein A is the aforedescribed bicyclic heterocyclic tertphosphine, mand n represent positive integers, each having a value of at least 1 andwhose sum is 4, and x represents a positive integer from 1 to 3.

Particularly suitable and novel catalysts of the invention include thetertiary organophosphine-cobalt-carbonyl complexes represented by theempirical formula wherein (I) is the aforedescribed tert-phosphine, inwhich the bicyclic portion of the molecule is saturated, containing Q,R, y and z members which are represented as above, m and n representpositive integers, each having a value of at least 1 and whose sum is 4,and x represents a positive integer from 1 to 3. Preferred catalysts ofthe above-defined class comprise those wherein R represents hydrogen orlower alkyl of 1 to 4 carbons such that no more than two R groups arealkyl at any one time and that each of said alkyl groups is attached toa different ring carbon, and Q represents hydrocarbyl containing from 1to 36 carbon atoms. A particularly preferred group of catalysts withinthe above-defined class are the bicyclic heterocyclictert-phosphine-cobalt-carbonyl complexes wherein the number of carbonsin the Q member of the tertiary phosphine (I) is from 4 to 30.

Another group of suitable and novel catalysts of the invention includethe tertiary organophosphine-cobaltcarbonyl complexes represented by theempirical formula )m )n]x (VII) wherein (III) is the aforedescribedmonophosphabicyclononatriene containing the member Q, m and 11 representpositive integers, each having a value of at least 1 and whose sum is 4,and x represents a positive integer from 1 to 3. Preferred catalysts ofthe above-defined class comprise those wherein Q represents hydrocarbylcontaining from 1 to 36 carbon atoms. A particularly preferred group ofcatalysts within the above-defined class are the P-hydrocarbylmonophosphabicyclononatrienecobalt-carbonyl complexes wherein the numberof carbons in the Q member of the monophosphabicyclononatriene (III) isfrom 4 to 30.

It is to be understood that the suitable novel catalysts identified bythe foregoing empirical Formula V may comprise two different A ligandsand even two or more of the A Co(CO) groups. For example, in thesuitable catalysts the novel complex between cobalt, carbon monoxide,and phosphine ligand may be monomeric in structure or may be composed ofseveral monomeric units. Thus, the novel complex may be present as adimer, e.g., a bis(phosphine) dicobalt hexacarbonyl.

It will be apparent from the preceding discussion that a variety ofbicyclic heterocyclic tert-phosphine ligands may be used in the novelcatalysts of the invention. In the nomenclature of such compounds,conventional numbering of the ring systems has been employed, as furtherillustrated by the following formulas:

(VIII) Representative examples of suitable catalysts of theabove-defined class comprise novel complexes between cobalt, carbonmonoxide, and one or a mixture of the following phosphine groups,numbered according to the aforesaid system, especially as thebis(phosphine) dicobalt he-xacarbonyl: 9-hydrocarbyl 9phosphabicyclonane in which the smallest 'P-containing ring contains atleast 5 atoms:

9-hydrocarbyl-9-phosphabicyclo [4.2.1]nonane;

9-aryl-9-phosphabicyclo[4.2.1]nonane,

such as 9-phenyl-9-phosphabicyclo[4.2.l]nonane;

(di)alkyl-9-aryl-9-phosphabicyclo [4.2.1]nonane,

such as 3 ,7 -dimethyl-9-phenyl-9-phosphabicyclo [4.2. 1

nonane and 3 ,8-dimethyl-9-phenyl-9-phosphabicyclo [4.2.1]nonane;

9-alkyl-9-phosphabicyclo[4.2.1]nonane,

such as 9-octadecyl-9-phosphabicyclo [4.2.1]nonane,

9-hexyl-9-phosphabicyclo[4.2.1]nonane,

9-eicosyl-9-phosphabicyclo[4.2.1]nonane, and

9-triacontyl-9-phosphabicyclo[4.2.1]nonane;

9-cycloalkyl-9-phosphabicyclo[4.2.1]nonane,

such as 9-cyclohexyl-9-phosphabicyclo[4.2.1]nonane and 9-(l-octahydropentalyl) -9-phosphabicyclo 4.2. l]

nonane;

9-cycloalkenyl-9-phosph abicyclo [4.2. l ]nonane,

such as 9-cyclooctenyl-9-phosphabicyclo[4.2.1]nonane;

9-hydrocarbyl-9-phospha'bicyclo[ 3 .3 l]nonane;

9-aryl-9-phosphabicyclo 3 .3 1 nonane,

such as 9-phenyl-9-phosph abicyclo [3 .3 l nonane;

9-alkyl-9-phosphabicyclo [3 .3 .1]nonane,

such as 9-hexyl-9 phosphabicyclo[3.3.1]nonane and9-eicosyl-9-phosphabicyclo [3.3 1 ]nonane;

(di) alkyl-9-aryl-9-phosphabicyclo 3 .3 .1 nonane,

such as 3,7-dimethyl-9-phenyl-9-phosphabicyclo[ 3 .3. l]

nonane and 3,8-dimethyl-9-phenyl-9-phosphabicyclo [3 .3 1 ]nonane;9-cycloalkyl-9-phosphabicyclo [3 .3 1 nonane, such as9-cyclohexyl-9-phosphabicyclo [3 .3 l nonane and 9-(l-octahydropentalyl) -9-phosphabicyclo [3 .3 1 nonane;9-cycloalkenyl-9-phosphabicyclo [3 3. 1 nonane, such as9-cyclooctenyl-9-phosph abicyclo 3 .3 .1]nonane;9-hydrocarbyl-9-phosphabicyclononatrie-ne in which the smallestP-containing ring contains at least 5 atoms;

9-hydrocarbyl-9-phosphabicyclo[4.2.1]-nona-2,4,7-

triene;

9-aryl-9-phosphabicyclo [4.2. l nona-2,4,7-triene,

such as 9-phenyl-9-phosphabicyclo [4.2.1]nona-2,4,7-

triene;

9-alkyl-9-phosphabicyclo [4.2. l nona-2,4,7-triene,

such as octadecyl-9-phosphabicyclo[4.2.1]nona-2,4,7-

triene,

9-hexyl-9-phosphabicyclo[4.2.1]nona-2,4,7-triene,

9-eicosyl-9-phosphabicyclo [4.2. l nona-2,4,7-triene, and

9-triacontyl-9-phosphabicyclo[4.2.1]nona2,4,7-triene;

9-cycloalkyl-9-phosphabicyclo[4.2.1]nona-2,4,7-triene,

such as 9-cyclohexyl-9-phosphabicyclo [4.2.1]nona-2,4,7-

triene;

8-phosphabicyclo[3.2.1 octane;

8-hydrocarbyl-8-phosphabicyclo [3 .2. 1 octane;

8-aryl-8-phosphabicyclo 3 .2. 1 octane,

such as 8-phenyl-8-phosphabicyclo 3 .2. l octane;

alkyl-8-aryl-8-phosphabicyclo [3 .2. l 1 octane,

such as 6-methyl-8-phenyl-8-phosphabicyclo [3 .2. 1]

octane;

8-alkyl-8-phosphabicyclo [3 .2. l octane,

such as 8-butyl-8-phosphabicyclo[ 3 .2. 1 octane,

8-eicosyl-8-phosphabicyclo[3.2. 1] octane,

8-triacontyl-S-phosphabicyclo [3 .2.1 ]octane, and

8-octadecyl-8-phosphabicyclo [3 .2. 1 octane;

8-cycloalkyl-8-phosphabicyclo[ 3 .2. 1 octane,

such as 8-cyclohexyl-8-phosphabicyclo[3.2.1]octane;

and the like. A suitable mixture as referred to hereinabove is a mixtureof 9-( l-octahydropentalyl)-9-phosphabicyclo[4.2.l]nonane and 9 (1octahydropentalyl)9- phosphabicyclo [3 .3.1]nonane.

Of these catalysts, those in which the tert-phosphine is and a mixturethereof with I: 00(00): P-O0H5 \Z 2 The novel catalysts can be preparedby a diversity of methods. A convenient method is to combine a cobaltsalt, organic or inorganic, with the desired phosphine ligand, forexample, in liquid phase followed by reduction and carbonylation.Suitable cobalt salts comprise, for example, cobalt carboxylates such asacetates, octanoates, etc. as well as cobalt salts of mineral acids suchas chlorides, fluoride-s, sulfates, sulfonates, etc. Operable also aremixtures of these cobalt salts. It is preferred, however,

8 that when mixtures are used, at least one component of the mixture becobalt alkanoate of 6 to 12 carbon atoms. The valence state of thecobalt may be reduced and the cobalt-containing complex formed byheating the solution in an atmosphere of hydrogen and carbon monoxide.The

reduction may be performed prior to the use of the catalysts or it maybe accomplished simultaneously with the hydroformylation process in thehydroformylation zone. Alternatively, the novel catalysts can beprepared from a carbon monoxide complex of cobalt. For example, it ispossible to start with dicobalt octacarbonyl and, by heating thissubstance with a suitablephosphine ligand of the class previouslydescribed, the ligand replaces one or more of the carbon monoxidemolecules, producing the desired catalyst. When this latter method isexecuted in a hydrocarbon solvent, the complex may be precipitated incrystalline form by cooling the hot hydrocarbon solution. X-ray analysesof the isolated crystalline solid show the crystalline form of thecomplex to be a dimer with a linear P-Co-Co-P group in the molecule. Forexample, bis'(9- phenyl-9-phosphabicyclo[3.3.1]nonane) dicobalthexacarbonyl, recrystallized from n-tridecanol, is a red-browncoloredcrystalline solid, M.P. 198-199" C. (dec.), exhibiting a strong carbonylabsorption band at a wave number of 1947 cm. and bis(9-phenyl 9phosphabicyclo- [4.2.1]nona-2,7-triene) dicobalt hexacarbonyl is aredbrown-colored crystalline solid exhibiting a strong carbonylabsorption band at a wave number of 1957 CHIC-1. This method is veryconvenient for regulating the number of carbon monoxide molecules andphosphine ligand molecules in the catalyst. Thus, by increasing theproportion of phosphine ligand added to the dicobalt octacarbonyl, moreof the carbon monoxide molecules are replaced.

In accordance with the invention, olefinic compounds are hydroformylatedto reaction products predominating in primary alcohols by intimatelycontacting the olefinic compound in liquid phase with carbon monoxideand hydrogen in the presence of the above-defined catalysts comprising acomplex of cobalt with certain phosphine ligands and carbon monoxide atwell defined conditions of temperature and pressure.

A particular advantage of the process of the invention resides in thecatalyst stability and its high activity for long periods of time atvery low pressures. Consequently, hydroformylation in accordance withthe present invention may be carried out at pressures well below 1000p.s.i.g. to as low as 1 atmosphere or less. Under comparable conditions,the conventional catalyst, dicobalt octacarbonyl, decomposes and becomesinactive. The invention is, however, not limited in its applicability tothe lower pressures, and pressures in the range from atmospheric up toabout 2000 p.s.i.g. are useful. Even higher ones, such as up to about5000 p.s.i.g., may be employed. The specific pressure preferably usedwill be governed to some extent by the specific charge and catalystemployed, as well as equipment requirements. In general, pressures inthe range of from about 300 to about 1500 p.s.i.g. and particularly inthe range of from about 400 to about 1200 p.s.i.g. are preferred. Theunique stability of the catalysts of the present invention at the lowerpressures makes the use of pressures below about 1500 p.s.i.g.particularly advantageous.

Temperatures employed will generally range between about and about 300C. and preferably between about and about 210 C., a temperature of aboutC. being generally satisfactory. Somewhat higher or lower temperaturesmay, however, be used.

The ratio of catalyst to the olefin to be hydroformylated is generallynot critical and may vary widely. It may be varied to achieve asubstantially homogeneous reaction mixture. Solvents are therefore notrequired. However, the use of solvents which are inert, or which do notinterfere to any substantial degree with the desired bydroformylationreaction under the conditions employed, may be used. Saturated liquidhydrocarbons, for example,

may be used as solvent in the process, as well as alcohols, ethers,acetonitrile, sulfolane, and the like. Molar ratios of catalyst toolefin in the reaction zone at any given instant between about 121000and about 10:1 are found to be satisfactory; higher or lower catalyst toolefin ratio may, however, be used, but in general it will be less than1:1.

The ratio of hydrogen to carbon monoxide charged may vary widely. Ingeneral, a mole ratio of hydrogen to carbon monoxide of at least about 1is employed. Suitable ratios of hydrogen to carbon monoxide comprisethose within the range of from about 1 to about 10. Higher or lowerratios may, however, be employed. The ratio of hydrogen to carbonmonoxide preferably employed will be governed to some extent by thenature of the reaction product desired. If conditions are selected thatwill result primarily in an aldehyde product, only one mole of hydrogenper mole of carbon monoxide enters into reaction with the olefin. Whenthe primary alcohol is the preferred product as in the presentinvention, two moles of hydrogen and one mole of carbon monoxide reactwith each mole of olefin. The use of ratios of hydrogen to carbonmonoxide which are somewhat higher than those defined by thesestoichiometrical values are generally preferred.

A signal advantage of the present invention as indicated above andfurther evidenced by the following examples is the ability to eifect thedirect, single-stage hydroformylation of the olefins to a reactionmixture wherein primary alcohols predominate over the aldehydes andbyproduct saturated hydrocarbons. The alcohols obtained from thestarting olefins are furthermore generally primarily the straight chainor normal isomers. By selection of reaction conditions within theabove-defined range, it is now possible to obtain a predominant portionof the product in the form of the normal or straight chain compoundrather than as its various branched-chain isomers. Generally, thealcohol is the desired end product and the catalysts defined herein willproduce this product under a relatively wide range of conditions.However, by varying the operating conditions within the range describedherein, the ratio of aldehyde to alcohol product may be varied somewhat.Adjustment of these variables also permits some control over theparticular isomer that will be produced.

A particularly valuable aspect of the invention resides in its abilityto eifect the direct, single-stage hydroformylation of internal normalolefins, having for example, from 4 to 19 carbon atoms to the moleculeto normal terminal alcohols having 5 to 20 carbon atoms to the molecule,respectively. Olefinic hydrocarbon fractions, such as, for example,polymeric olefinic fractions, cracked wax fractions, and the like,containing substantial proportions of internal olefins are readilyhydroformylated to fractions of hydroformylated products comprisingmixtures of terminal aldehydes and alcohols having one more carbon thanthe olefins inrthe charge and wherein these primary alcohols are thepredominant reaction product. Such suitable feeds consisting of olefinichydrocarbon fractions include, for example, C C C C and higher olefinicfractions as well as olefinic hydrocarbon fractions of wider boilingranges such as Cr, C C1447 olefinic hydrocarbon fractions and the like.

Under the above-defined conditions, the olefinic charge reacts withcarbon monoxide and hydrogen with the formation of reaction productscomprising primary alcohols having one more carbon atom per moleculethan the olefin charged.

The reaction mixtures obtained may be subjected to suitable catalyst andproduct separating means comprising one or more such steps, for example,as stratification, solvent extraction, distillation, fractionation,adsorption, etc. Catalyst, or components thereof, as well as unconvertedcharge, may be recycled in part or entirely to the reaction zone.

The process of this invention is generally applicable to thehydroformylation of any aliphatic or cycloaliph-atic compound having atleast one aliphatic carbon-to-carbon unsaturation, especially anethylenic carbon-to-carbon bond. Thus, it is applied to thehydroformylation of ole- 5 fins having, for example, from 2 to 19carbons to reaction mixtures predominating in aliphatic aldehydes andalkanols having one more carbon atom than the starting olefin. Theinvention is used to advantage in the hydroformylation ofcarbon-to-carbon ethylenically unsaturated linkages in hydrocarbons.Monoolefins such as ethylene, propylene, butylene, cyclohexene,l-octene, dodecene, 1- octadecene and dihydroaphthalene are a fewexamples of suitable hydrocarbons. Suitable hydrocarbons include bothbranchedand straight-chain, as well as cyclic, compounds having one ormore of these ethylenic or olefinic sites. These sites may beconjugated, as in 1,3-butadiene, or non-conjugated, as in 1,5-hexadieneand bicyclo[2.2.1] hepta-2,5-diene. In the case of polyolefins, it ispossible to hydroformylate only one of the olefinic sites or several orall of these sites. The unsaturated carbon-to-carbon olefinic linkagesmay be between terminal and their adjacent carbon atoms, as inl-pentene, or between internal chain carbon atoms, as in 4-octene.

The process and novel catalyst of this invention may also be used tohydroformylate ethylenic carbon-to-carbon linkages of non-hydrocarbons.Thus, it is possible to hydroformylate olefinically unsaturatedalcohols, aldehydes, and acids to corresponding alcohols, aldehydes, andacids containing an aldehyde or hydroxy group on one of the carbon atomspreviously involved in the olefinic bond of the starting material;unsaturated "aldehydes yield principally diods. The following are a fewspecific examples of different types of olefinic compounds that may behydroformylated in accordance with the invention:

l-hexene l-heptanal CH (CH2) CHzOH isometric products l-heptanolcatalyst CHZ=CHCI C0 H2 T ClCHzCHzCHzOH andlor A-acetoxybutanol catalystU C0 H2 T (wicno and/o, m-CIfiOH cyclopentene formylcyclopentanecatalyst C2H50COCH=CHOOOC2HB C0 H;

CHzOH oznto O O QHCH2C O O C2H5 and/or diethyl a-formylsuceinate CHOdiethyl a-methylolsuccinate CH2CH=CH2 catalyst allyl benzene CH C 0 0CH2CHZCHQCH2OH isometric products cyclopentylcarbinol i I I v 1CzHsOCOCHCHzCOOCzHs CHZCHZCHZOHO and/or 'y-phenylbutyraldehydeCH2CHZCH2CH2OH isomeric products A-phenylbutanol The olefinic charge maycomprise two or more of the above-defined suitable olefins. Olefinichydrocarbon fractions are hydroformylated under the conditionsabovedefined to mixtures of aldehydes and alcohols in which the alcoholspredominate.

The following examples are illustrative of the process of thisinvention. It is to be understood that these examples are given only forillustration and are not to be construed as limiting the invention tothe details thereof.

EXAMPLES l and 2 Cobalt catalysts of cobalt in complex combination withcarbon monoxide and the below-indicated tertiary phosphine ligands wereutilized with l-dodecene as olefin. The catalysts were prepared in situ,in the equipment to be described, from cobalt octanoate.

The reactor was a BOO-ml. stainless steel magnetically stirred autoclaveoperated at 1250 rpm. and connected to a source of a premixedhydrogen-carbon monoxide gas delivered at any desired constant pressure.The components forming the catalyst (e.g., tertiary phosphine and cobaltoctanoate) and the olefin, l-dodecene, were charged to the reactor; thereactor was closed, evacuated, and pressured with H CO gas until allforeign gases were displaced. The reactor was then heated undersufficient H +CO pressure so that the final pressure at reactiontemperature was about 1000 p.s.i.g. After the teperature wasequilibrated, the pressure reduction was recorded. The reactionconditions and results are tabulated in Table 1.

Example 1 below, utilizing the commercially availabletri-n-butylphosphine as the phosphorus ligand, was taken as acomparative control. A comparison between Example 1 and Example 2 showsthat the quantity of undesirable saturated hydrocarbon by-product formedwhen using as ligand the bicyclic heterocyclic tert-phosphine of theinvention is less by a factor of about one-half than that formed whenusing tri-n-butylphosphine, in spite of the fact that the hydrogenatingactivity of the novel catalyst in Example 2 was sufficient to insureessentially complete hydrogenation of the intermediate aldehyde.

time of 3 hours in the presence of a catalyst consisting oftriphenylphosphine-cobalt-carbonyl at a phosphine/ cobalt mole ratio of2:1. There was obtained a conversion of 98.8% of the olefin with aselectivity to C alcohols of 86.1%. Of the C alcohols obtained, 52% wasthe linear, straight-chain n-tridecanol, the remainder branched-chainalcohols.

Similarly l-dodecene was hydroformylated by reaction with carbonmonoxide and hydrogen in a H /CO mole ratio of 2:1, at 183 C., apressure of 1000 p.s.i.g., with a contact time of 6 hours in thepresence of a novel catalyst consisting of a mixture of9-eicosyl-9-phosphabicyclo- [4.2.l]nonane-cobalt-carbonyl and9-eicosyl-9-phosphabicyclo[3.3:l]nonane-cobalt-carbonyl at aphosphine/cobalt mole ratio of 1.5: 1. There was obtained a conversionof the olefin of 98.5 with a selectivity to C alcohols of 86.9%. Of theC alcohols obtained, 89% was the linear, straight-chain n-tridecanol,the remainder branchedchain alcohols.

Similarly 1dodecene was hydroformylated by reaction with carbon monoxideand hydrogen in a H /CO mole ratio of 2:1, at 200 C., a pressure of 1200p.s.i.g., with a contact time of 1.3 hours in the presence of a novelcatalyst consisting of 9-phenyl-9-phosphabicyclo[4.2.1]-nona-2,4,7-triene-cobalt-carbonyl at a phosphine/cobalt mole ratio of1.521. There was obtained a conversion of the olefin of 98.6 with aselectivity to C alcohols of 88.6%. Of the C alcohols obtained, 68% wasthe linear, straight-chain n-tridecanol, the remainder branched-chainalcohols.

It is seen from the foregoing results that with triphenylphosphine asthe phosphorus ligand of the catalyst the predominance of the highlydesirable linear straight-chain or normal alcohol over thebranched-chain isomers is not as great as with novel catalyst in whichthe phosphorus ligands are the bicyclic heterocyclic tert-phosphines ofthe invention.

EXAMPLE 4 l-dodecene was hydroformylated in the manner described intheprevious examples with the addition that alkali was added in aKOH/cobalt mole ratio of 0.75:1. By reaction with carbon monoxide andhydrogen in a H /CO mole ratio of 2:1, at ZOO-203 C., a pressure of 1000p.s.i.g., with a contact time of 5.5 hours in the presence of a catalystconsisting of trilaurylphosphine-cobaltcarbonyl at a phosphine/ cobaltmole ratio of 1.5: 1, there was obtained a conversion of 99.2% of theolefin with a conversion to primary C alcohols of 83.2%.

Similarly l-dodecene was hydroformylated at 183l85 C. with a contacttime of six hours in the presence of a novel catalyst consisting of amixture of 9-eicosyl-9-phos- TABLE 1.HYDROFORMYLATION OF l-DODECENEExample 1 2 3 Phosphine Ligand Tri-n-butyl Mixture of Q-phenyl-Q-phenyl-Q-phosphabiphosphine. 9-phosphabicyelo cycle-[4.2.1]nona-[4.2.1]nonane and 2,4,7-trieue. Q-phenyl-Q-phosphableyclo[3.3.1]-110118-116. Cobalt, percent wt 0.2 0.2 0.2. Phosphine/cobalt mole ratio.2-- 2-- 2. HQ/GO mole ratio 2.1-. 2.1-- 2.1. Temperature, (1. 19820198-2 198200 Pressure, p.s.i.g 1,000-.- 1,200- 1,200. Time required for99% conversion, hr- 3.6 1.5 1.5. Conversion of l-dodeeene, percent.--99.1 98.6. Conversion to saturated hydrocarbon, 20.4 11.8 9.6.

percent. Convsrsion to primary alkanols, per- 78.2 87.6 88.6.

cen

EXAMPLE 3 l-dodecene was hydroformylated in the manner described in theprevious examples by reaction with carbon monoxide and hydrogen in a H/CO mole ratio of 2:1, at 198-203 C., a pressure of 1000 p.s.i.g., witha contact phabicyclo[4.2.1]nonane-cobalt-carbonyl and 9-eicosyl-9-phosphabicyclo[3.3.1]nonane-cobalt-carbonyl. There was obtained aconversion of 98.5% of the olefin with a conversion to primary Calcohols of 86.9%.

Similarly l-dodecene was hydroformylated at 185 C. with a contact timeof five hours at a pressure of .1200

13 p.s.i.g. in the presence of a novel catalyst consisting of a mixtureof 9'-phenyl-9-phosphabicyclo[4.2.1]nonane-cobalt-carbonyl and9-phenyl-9-phosphabicyclo[3.3.1]nonane-cobalt-canbonyl. There wasobtained a conversion of 99.4% of the olefin with a conversion toprimary C alcohols of 88.2%.

Similarly l-dodecene was hydroformylated at 175 C. with a contact timeof five hours at a pressure of 1200 p.s.i.g. in the presence of a novelcatalyst consisting of 9-phenyl 9phosphabicyclo[4.2.1]nona-2,4,7-triene-cobalt-carbonyl. There wasobtained a conversion of 98.6% of the olefin with a conversion toprimary C alcohols of 88.6%.

The foregoing results of obtaining a similar conversion at about thesame contact time but at approximately 15 to 25 C. lower temperaturedemonstrate the exceptionally rapid rate of hydroformylation achieved bythe new and improved hydroformylation catalyst in which thephosphorus'ligands are the bicyclic heterocyclic tert-phosphines of theinvention as compared with the rate achieved when atrialkylphosphine'such as trilaurylphosphine is the phosphorus ligand ofthe catalyst.

EXAMPLE l-dodecene was hydroformylated in the manner described inExample 5 by reaction with carbon monooxide and hydrogen in a H /CO moleratio of 2:1, at 163165 C., a pressure of 1200 p.s.i.g., with a contacttime of 11 hours in the presence of a catalyst consisting of 9phenyl-9-ph0sphabicyclo[3.3.1]nonane-cobalt-carbonyl at aphosphine/cobalt mole ratio of 1.5 :1. There was obtained a conversionof the olefin of 95% with a conversion to primary C alcohols of 83.4%.Of the C alcohols obtained, 87.6% was the linear, straightchainn-tridecanol.

EXAMPLE 6 l-dodecene was hydroformylated in the manner described inExample 4 by reaction with carbon monoxide and hydrogen in a H /CO moleratio of 2:1, at 183 185 C., a pressure of 1200 p.s.i.g., With a contacttime of 6 hours in the presence of a catalyst consisting of a mixture of9-eicosyl-9-phosphabicyclo[4.2.1]nonane-cobalt-carbonyl and 9eicosyl-9-phosphabicyc1o[3.3.1]nonane-cobalt-carbonyl at aphosphine/cobalt mole ratio of 1.3:1. There was obtained a conversion ofthe olefin of 98.5% with a conversion to primary C alcohols of 86.9% andto by-product saturated hydrocarbon of 11.6%. Repetition of this examplewith a decrease in pressure to 600 p.s.i.g. and slight increase incontact time to seven hours yielded a conversion about equal to thatobtained at the higher pressure, 98.4% of the olefin, 86.6% to primary Calcohols and 11.7% to by-product saturated hydrocarbon.

EXAMPLE 7 A series of internal normal olefins was prepared bychlorination of straight-chain paraffins followed by dehydrochlorinationto a corresponding mixture of substantially internal olefins containingless than 5% of the l-olefin. By this method internally unsaturatedtetradecenes, internally unsaturated tridecenes, internally unsaturateddodecenes, and internally unsaturated undecenes were each prepared. Eachof these internal olefins was hydroformylated in the manner described inExample 4 by reaction with carbon monoxide and hydrogen in a H /CO moleratio of 2: 1, at 170 C., a pressure of 1200 p.s.i.g., with a contacttime of 7.5 to 9 hours in the presence of a catalyst consisting of amixture of 9 eicosyl 9 p'hosphabicyclo[4.2.1]nonanecobalt-carbonyl and 9eicosyl 9 phosphabicyclo- [3.3.1]nonane-cobalt-carbonyl at a weightpercent cobalt of 0.4 and a phosphine/cobalt mole ratio of 2:1. Theresults are tabulated in Table 2, demonstrating the effectiveness of thenovel catalysts to convert internal normal olefins to a substantialquantity of normal terminal alcohols.

TABLE 2.HYDROFORMYLATION OF INTERNAL OLEFINS A further economicadvantage obtainable with the catalysts of the present invention isthat, in continuous hydroformylation processing, longer catalyst life isachieved by virtue of the ability to hydroformylate at lowertemperatures Additionally, these catalysts are more stable during thehydroformylation process owing to the fact that their resistance tooxidation and degradation is higher than that of catalysts having atrialkylphosphine ligand.

Also the bicyclic heterocyclic tertiary phosphine-cobalt-carbonylcomplexes of the present invention are particularly useful ashydrogenation catalysts for hydrogenating aldehydes to alcohols usingcommercially available mixtures of hydrogen containing carbon monoxide.

We claim as our invention:

1. A catalyst composition consisting essentially of cobalt in complexcombination with carbon monoxide and a monophosphabicyclohydrocarbon inwhich the phosphorus atom is substituted with non-acetylenic hydrocarbyland is a bridge linkage and which monophosphabicyclohydrocarbon has asmembers of the bicyclic skeletal structure 7 to 8 carbon atoms togetherwith the phosphorus atom, wherein the mole ratio ofmonophosphabicyclohydrocarbon to co'balt is an integer between 1 and 3,inclusive, and the mole ratio of monophosphabicyclohydrocarbon andcarbon monoxide to cobalt is 4.

2. A catalyst composition in accordance with claim 1 wherein saidmonophosphabicyclohydrocarbon is of the formula:

Where Q represents non-acetylenic hydrocarbyl, R is selected from thegroup consisting of hydrogen and lower alkyl, and y and z representpositive integers whose sum is from 2 to 3.

3. The composition in accordance with claim 2 wherein said Q representsnon-acetylenic hydrocarbyl of from 1 to 36 carbon atoms and said R isselected from the group consisting of hydrogen and alkyl of from 1 to 4carbon atoms such that no more than two R groups are alkyl at any onetime and that each of said alkyl groups is attached to a different ringcarbon.

4. The composition in accordance with claim 2 wherein the sum of thecarbon atoms of said Q and said R is no greater than 38 carbon atoms.

5. The composition in accordance with claim 3 wherein said y and zrepresent positive integers whose sum is 3.

6. A catalyst composition in accordance with claim 1 wherein saidmonophosphabicyclohydrocarbon is of the formula:

where Q represents non-acetylenic hydrocarbyl.

7. The composition in accordance with claim 6 wherein said Q representsnon-acetylenic hydrocarbyl of from 1 to 36 carbon atoms.

8. The composition in accordance with claim 7 wherein saidmonophosphabicyclohydrocarbon is 9-pheny1-9-phosphabicyclo[4.2.1]nona-2,4,7-triene.

9. The composition in accordance with claim wherein Q is aryl.

10. The composition in accordance with claim 9 wherein saidmonophosphabicyclohydrocarbon is 9-phenyl-9-phosphabicyclo[4.2.1]nonane.

11. The composition in accordance wtih claim 9 Wherein saidmonophosphabicyclohydrocarbon i 9-phenyl-9- phosphabicyclo [3 .3.1]nonane.

12. The composition in accordance with claim 9 wherein saidmonophosphabicyclohydrocarbon is a mixture of9-phenyl-9-phosphabicyclo[4.2.1]nonane and 9-phenyl-9- phosphabicyclo [3.3. 1 ]nonane.

13. The composition in accordance with claim 5 Where in Q is alkyl.

14. The composition in accordance with claim wherein saidmonophosphabicyclohydrocarbon is eicosy1-9-phosphabicyclo [4.2.1]nonane.

15. The composition in accordance with claim 13 wherein saidmonophosphabicyclohydrocarbon is 9 eicosy1-9-phosphabicyclo [3 .3 1nonane.

16. The composition in accordance with claim 13 wherein saidmonophosphabicyclohydrocarbon is a mixture of9-eicosyl-9-phosphabicyclo[4.2.1]nonane and 9- eicosyl-9-phosphabicyclo[3.3. 1 nonane. v

17. The composition in accordance with claim 5 wherein Q is cycloalkyl.

18. The composition in accordance with claim 17 wherein saidmonophosphabicyclohydrocarbon is 9-(1- octahydropentalyl-9-phosphabicyclo [4.2.1]nonane.

19. The composition in accordance with claim 17 wherein saidmonophosphabicyclohydrocarbon is 9-(1-octahydropentalyl)-9-phosphabicyclo [3 .3 .1]nonane.

20. The composition in accordance with claim 17 wherein saidmonophosphabicyclohydrocarbon is a mixture of 9-(l-octahydropentalyl)-9-phosphabicyclo[4.2.1]- nonane and9-(l-octahydropentalyl)-9-phosphabicyclo- [3.3.1]nonane.

References Cited UNITED STATES PATENTS 3,168,553 2/1965 lslaugh 260-497TOBIAS E. LEVOW, Primary Examiner A. P. DEMERS, Assistant Examiner U.S.Cl.'X. R. 252-43; 260599, 604, 618, 638

